Truth is, no relationship comes with a lifetime guarantee. Even men and women who grew up in stable homes, who attend church and consider themselves Christians, who promise "until death do us part," can have it all fall apart. Crumby way to start huh?

We know that applying biblical principles to marriage will give us a stronger foundation. We know this, but what are we doing about it?

According to author Gary Thomas, we're not asking the right questions. What if your relationship isn't as much about you and your spouse as it is about you and God?

Instead of asking why we have struggles in the first place, the more important issue is how we deal with them.

In Sacred Marriage, Thomas has not written your typical "how to have a happier relationship" book. Rather, he asks: How can we use the challenges, joys, struggles and celebrations of marriage to draw closer to God? What if God designed marriage to make us both happy and holy?

Viewing Marriage Realistically

"We have to stop asking of marriage what God never designed it to give — perfect happiness, conflict-free living, and idolatrous obsession," Thomas explains.

Instead, he says, we can appreciate what God designed marriage to provide: partnership, spiritual intimacy and the ability to pursue God — together. So, what does Thomas think is the most common misconception Christians have about marriage?

"Finding a 'soul mate' — someone who will complete us," he says. "The problem with looking to another human to complete us is that, spiritually speaking, it's idolatry. We are to find our fulfillment and purpose in God . . . and if we expect our spouse to be 'God' to us, he or she will fail every day. No person can live up to such expectations."

Everyone has bad days, yells at his or her spouse, or is downright selfish. Despite these imperfections, God created the husband and wife to steer each other in His direction.

Thomas offers an example: "When my wife forgives me . . . and accepts me, I learn to receive God's forgiveness and acceptance as well. In that moment, she is modeling God to me, revealing God's mercy to me, and helping me to see with my own eyes a very real spiritual reality."

While it's easy to see why God designed an other-centered union for a me-centered world, living that way is a challenge. So when bills pile up, communication breaks down and you're just plain irritated with your husband or wife, Thomas offers these reminders to help ease the tension:

• God created marriage as a loyal partnership between one man and one woman.
• Marriage is the firmest foundation for building a family.
• God designed sexual expression to help married couples build intimacy.
• Marriage mirrors God's covenant relationship with His people.

We see this last parallel throughout the Bible. For instance, Jesus refers to Himself as the "bridegroom" and to the kingdom of heaven as a "wedding banquet."

These points demonstrate that God's purposes for marriage extend far beyond personal happiness. Thomas is quick to clarify that God isn't against happiness per se, but that marriage promotes even higher values.

"God did not create marriage just to give us a pleasant means of repopulating the world and providing a steady societal institution to raise children. He planted marriage among humans as yet another signpost pointing to His own eternal, spiritual existence."

Serving Our Spouse

He spends the entire evening at the office — again. She spends money without entering it in the checkbook. He goes golfing instead of spending time with the kids. From irritating habits to weighty issues that seem impossible to resolve, loving one's spouse through the tough times isn't easy. But the same struggles that drive us apart also shed light on what we value in marriage.

"If happiness is our primary goal, we'll get a divorce as soon as happiness seems to wane," Thomas says. "If receiving love is our primary goal, we'll dump our spouse as soon as they seem to be less attentive. But if we marry for the glory of God, to model His love and commitment to our children, and to reveal His witness to the world, divorce makes no sense."

Couples who've survived a potentially marriage-ending situation, such as infidelity or a life-threatening disease, may continue to battle years of built-up resentment, anger or bitterness. So, what are some ways to strengthen a floundering relationship — or even encourage a healthy one? Thomas offers these practical tips:

• Focus on your spouse's strengths rather than their weaknesses.
• Encourage rather than criticize.
• Pray for your spouse instead of gossiping about them.
• Learn and live what Christ teaches about relating to and loving others.

Young couples in particular can benefit from this advice. After all, many newlyweds aren't adequately prepared to make the transition from seeing one another several times a week to suddenly sharing everything. Odds are, annoying habits and less-than-appealing behaviors will surface. Yet as Christians, we are called to respect everyone — including our spouse.

Thomas adds, "The image I use in Sacred Marriage is that we need to learn how to 'fall forward.' That is, when we are frustrated or angry, instead of pulling back, we must still pursue our partner under God's mercy and grace."

Lastly, Thomas suggests praying this helpful prayer: Lord, how can I love my spouse today like (s)he's never been loved and never will be loved?

"I can't tell you how many times God has given me very practical advice — from taking over some driving trips to doing a few loads of laundry," Thomas says. "It's one prayer that I find gets answered just about every time."

While other marriage books may leave us feeling overwhelmed, spotlighting our shortcomings and providing pages of "relationship homework," Sacred Marriage makes it clear that any couple can have a successful, happy and holy marriage.

With a Christ-centered relationship, an other-centered attitude and an unwavering commitment to making it work, your marriage can flourish — just as God designed.